Layout centering tool



"May 20, 1930. w MEESEL I 1,758,959

' LAYOUT CENTERING TOO L Filed May 7, 1928 v INVENTOR Z782??? Wflleese I BY 2 Z ATTORNEY particularly, to a center punch having means Patented May 20, 1930 i PATENT OFFICE HENRY W. MEESED, OF NEWARK, NEW JERSEY LAYOUT OENTERING TOOL Application filed May 7,

The present invent-ion relates, generally,.to a center punch adapted for use in laying out work for machinists and tool makers and other work and the invention relates, more associated therewith for centering the punch with a high degree of precision and accuracy.

An object of the invention is to provide a center unch having knife edges arranged in operative relation therewith and adapted to engage in grooves or lines scratched in the surface of a piece of work to accurately and precisely position the center punch above a point at which a centering mark is to be made with the punch.

Various other objects and advantages of the invention will be obvious from the following particular description of forms of apparatus embodying the invention or from an inspection of the accompanying drawings; and the invention also consists in certain new and useful features of construction and combinations of parts hereinafter set forth and claimed.

In the accompanying drawings there are shown for purposes of illustration one form of ap aratus with certain modifications thereof em odying the invention, in which Figure 1 is an elevation view;

Figure 2 is a top plan view;

Figure 3 is a bottom plan view;

Figure 4 is a bottom plan view of a modified form; and

Figure 5 is a perspective view showing a piece of work with centering scratch lines thereon, greatly enlarged.

In all the views similar characters of reference indicate corresponding or similar parts.

Referring now. to the drawing the reference character 1 indicates a shank having a head 2 at the lower end thereof on the outer end of which latter is a flat face 3 accurately aligned at right angles to the axis of'said shank 1, and longitudinally through said shank 1 there extends a cylindrical bore 4 accurately aligned with its axis coincident with the axis of the shank 1. Extending through said bore 4 and makin an accurate sliding fit therein is the punch 5 aving its point 6 extending out beyond said face 3 and having its opposite 1928. Serial No. 275,642.

end extending out beyond the other end of said shank 1.

Set in said face 3 to extend downwardly therefrom accurately at right angles thereto are two pairs of studs 7, 7 and 8, 8 arranged circumferentially about said punch point 6. Each of said studs 7, 8 is driven with a taper fit into a corresponding bore 9 so that is can be removed and replaced. The outer end of each of said studs 7, 8 is accurately sharpened at an angle of about 40 to an accurate knife edge, all of the knife edges being aligned to extend accurately along lines which extend transversely through the axis of said punch 5. It is necessary that said knife edges have a very accurate alignment so that a line between the knife edges of studs 7 7 will cross the line between the knife edges of said studs 8, 8 accurately at the axis of said punch 5.

As shown the line connecting the knife edges of said studs 7, 7 is accurately at ninety degrees to the line connecting the knife edges of studs 8, 8. Other angular relations could be used but that described is preferred because cross lines in the work for centering the punch through said knife edges can be more accurately laid out with speed at ninety degrees to each other than at other angles.

In Figure 5 is illustrated a block of work 9 on the upper face of which have scribed the two scratch lines 10, 10 which intersect each other accurately at ninety degrees at a point where a hole is to be drilled, for example. Said scratch lines 10, 10 are preferably made with a scriber having its point defined by faces or-slopes at sixty degrees apart so that with very.li'ght scratches the knife edges of studs can accurately engage the bottoms of the scratches. The lines 10, 10 are scratched lightly and accurately to intersect at the exact point at which a punch mark is to be made, and these having been made the centering tool isplaced with the knife edges of studs 7, 7 in one of said lines 10 and the knife edges of studs 8, 8 in the other line whereby said punch point 6 is accurately aligned above the point of intersection of said lines 10, 10. The tool is firmly held in this position while the upper end of punch 5 is struck with a hammer to make a punch mark at the intersection of the lines. By this manner and means a deep centering punch mark for drills can be made with the high degree of accuracy required in the making of tools and dies, and with such a deep mark accurately made the laying out of guide circles and marks, such as is usually done, is unnecessary because the deep accurate mark will keep the drill centered until it has itself cut a hole deep enough to insure the accurate completion of the bore made thereby.

It will be apparent that the alignment of the knife edges need not be as described but can be made, for example, to position the punch over a point which is offset at a given accurate distance from a point of intersection of lines through and along the knife edges. Also three knife edges can be used with their alignment at 120 apart to center the punch accurately at a center.

In Figure 1 of the drawing is shown a bottom plan view of a tool similar to that of Figures 1 to 3 in which the head 2 is cylindrical except that a sector is omitted to bring the chord thereof close to the bore 4 and punch point 6. Opposite the chord of the omitted sector is a stud 11 which has its knife edge accurately aligned with the center of said bore 4, and at ninety degrees from said stud 11, one on each side thereof, are the studs 12, 12 whose knife edges are accurately aligned with each other and with the center a of said bore 4, the knife edges of all of the studs 11, 12, 12 being in a common plane. This embodiment of the invention is adapted for making punch marks close to a wall or projection which would naturally prevent the use of the four studded tool of Figure 1.

A great advantage of the use of knife edges is that the punch can be very accurately aligned thereby, and also it can be aligned thereby repeatedly with a high degree of accuracy because the knife edge when made of tempered tool steel, for example, will kee their edges along time. Further, the knifii edges can be quickly sharpened, accurately with respect to each other and to the punch, the knife edges admitting of grinding along lines parallel to the edges to be formed with speed, accuracy and cheapness of operation. It will be understood that the knife edges can be formed on parts which are unitary with the punch guiding shank.

While I have shown and described and have pointed out in the annexed claims certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details of the devices illustrated and in their use and operation may be made by those skilled in the art without departing from the spirit of the invention.

I claim:

1. fr centering punch having aligning means thereon and comprising, an elongated shank having a longitudinal axial bore therethrough, a marking punch adapted to extend through said bore with the punch point at one end and the blow receiving end at the other, said punch point being centered on the longitudinal axis of said shank, and members arranged on said shank and having knife edges arranged in a common plane extendin at right angles to the longitudinal axis of said shank, each of said knife edges being aligned radially with the axis of said shank.

2. A centering punch having aligning means thereon and comprising an apertured shank having at one end thereof a number of knife edges arranged in a common plane and radially aligned with respect to a common point as a center, and a marking punch contained within the aperture of said shank with its point adapted for punching movement along a line passing at right angles through, the common plane of said knife edges at said common point.

3. A centering punch comprising a shank having aligning means thereon, said aligning means comprising, a plurality of knife edges arranged in a common plane, and a marking punch carried by said shank and arranged for movement along a line normal to said common plane and in predetermined relation to the lines in said plane passing along said knife edges.

4. A centering punch having aligning means thereon and comprising, an elongated shank having a longitudinal cylindrical bore, a punch having a sliding fit in said bore and adapted to extend therethrough from one end to the other with a point at one end and a blow receiving end at the other, and studs securely inserted in said shank at one end and arranged about the opening of said bore thereat, said studs having knife edges arranged in a common lane which is perpendicular to the axis 0 said bore, said knife edges being in predetermined relation to said axis.

5. A centering punch having aligning means thereon and comprising, an elongated shank having a longitudinal cylindrical bore, a punch having a sliding fit in said bore and adapted to extend therethrough from one end to the other with a point at one end and a blow receiving end at the other, and studs securely inserted in said shank at one end and arranged about the opening of said bore thereat, said studs having knife edges arranged in a common plane which is perpendicular to the axis of said bore, said studs being four! in number with their knife edges arranged radially about said axis at ninety degree intervals.

In testimony, that I claim the invention set forth above I have hereunto set my hand this third day of May, 1928.

HENRY W. MEESEL. 

